Liquified petroleum burner



P '9, 1958 v G. J. HEBERLEIN 2,851,096

LIQUIFIED PETROLEUM BURNER Filed March 8, 1954 INVENTOR.

George J. Heber/ein I m warm ,4 TTORNEY 1. United States Patented Sept. 9, 1958 LIQUIFIED PETROLEUM BURNER George J. Heberlein, Ault, Colo. Application March 8, 1954, Serial No. 414,641 2 Claims. c1. 158-79) This invention relates to petroleum burners of the type which burn heavy liquifiable gaseous hydrocarbons such as propane and more particularly to a novel and improved burner head for heavy gaseous hydrocarbons which are commonly available in containers as liquids under pressure and will be hereinafter referred to as propane or propane gas. The primary object of the invention is to provide a novel and improved burner head for propane gas which may be directly connected with a tank of propane without the use of any intermediate pump or vaporizer and without the use of any fuel supply orifice control means in the burner head.

Another object of the invention is to provide a novel and improved burner head for propane gas which is formed as a direct unobstructed conduit through which the fuel may pass.

Propane gas is commonly supplied in cylinders or bottles as a liquid under pressure which will quickly vaporize at atmospheric pressure and ordinary temperatures. The availability and efliciency of propane gas makes it desirable for many purposes. One important purpose is to use the gas in flame-jet-burners of the type which generates and projects a blast of flame a substantial distance from the burner and is used primarily for weed burning and the like. type are expensive and complicated because it .is necessary to include in the fuel supply line to the burner a vaporizer, pump, and fuel control means such as a restricted orifice within or adjacent to the burner head. An orifice or like control naturally tends to restrict the flow of gas, and the natural pressure within the propane container is usually insuflicient to cause the gas to flow through the burner to create the desired intense blast of flame. It follows that the initial cost and maintenance of such burners is large, primarily because the orifice controls have to be carefully made and frequently replaced.

With such in view the present invention was conceived and developed and comprises inessence a burner head for gaseous fuels such as propane which does not require pumps and which provides a direct unobstructed conduit through the burner.

It follows that further objects of the invention are to provide an improved burner head for propane gas which: (a) is formed as a direct unobstructed conduit through which .the fuel may pass; (b) is adapted to eject an intense, heavy blast of flame responsive to the natural vaporizing pressure of the liquid propane and without additional pressurizing means; projects a controlled blast of flame which may have a selected spread such as a fan-shaped pattern; (d) is especially adapted for weed burning and like operations; (2) is an exceptionally small, compact unit for its fuel consumption capacity and size of the flame ejected therefrom; and (f) is an economical, easily-built, maintenance-free, rugged and durable unit.

With the foregoing and other objects in view, all of which more fully hereinafter appear, my invention com- Conventional burners of this prises certain novel and improved constructions, combinations, and arrangement of parts andelements as here-;

after described and as defined in the appended claims and illustrated in preferred embodiment in the accompanying drawing in which:

Figure 1 is an elevational view, somewhat diagrammatic in nature, of a complete burner unit ready for use.

Figure 2 is a plan view of the improved burner head per se as taken from the indicated arrow 2 at Fig. 1 but on an enlarged scale.

Figure 3 is an end view of the burner as from the indicated arrow 3 at Fig. 2 but on a further enlarged scale.

Figure 4 is enlarged fragmentary sectional detail as taken from the indicated line 4-4 at Fig. 2.

Referring more particularly to the drawing, the burner unit illustrated diagrammatically at Fig. 1 will include a conventional fuel supply tank P of liquid propane under pressure, a valve Vat the outlet of the tank, a fuel line L connected to the valve and the burner head at the end of the fuel line which 'will be hereinafter described in detail. The fuel line L may include a length of flexible hose F and a handle H adjacent to the burner head and may include other valves, not shown, or other desirable arrangements of conduits in any suitable manner to provide for the control and flow of liquid fuel from the tank P to the burner head.

The burner head is carried upon a short length or stub 10 of ordinary rigid pipe which is about an inch inside diameter or substantially the same size as the fuel line conduit L to which it is connected. The connection of this stub pipe 10 to the fuel line may be with any suitable fitting, or it may be threaded as at 10a to be turned into an ordinary coupling at the end of the fuel line L or in the end of the handle H as illustrated.

The burner head itself is formed of a length of smaller size steel tubing 11 which is wound into a serpentine shaped coil 12 in the general shape of a flattened cone or frustro-conical open-end arrangement with the base opening forming the mouth end 16 from whence flame is discharged and the apex opening forming the rear end 17 wherein gas and air enter the burner for movement therethrough.

One end of the tubing 11 is connected to the extended end of the stub pipe 10 as by flaring and welding as at 11a. From this connection the tube is turned upwardly and to one side of the stub pipe 10 and wound in fiattened loops to form the coil 12 with the stub pipe lying outside and against a flattened side of the coil. The opposite end of the tube, at the rear end 17, is turned away from the coil to lie against and in alignment with the stub pipe 10 for a short distance 13, and the extreme end portion 14 is bent back in a -degree loop so that its discharge opening 15 is facing the coil 12 and is centered in spaced relationship from the smaller rear end 17 of the coil.

At various suitable points the tubing forming the coil 12 is welded to the pipe 10, as at 10!), and each loop of the coil is welded to its adjacent loop as at selected points 12a to form an integrated rigid unit to hold the coils of the tubing 11 closely together without any substantial space between the coil loops.

In actual practice, I use about 40 feet of onequarter inch inside diameter steel tubing 11, connecting it to the lower end of the stub pipe 10 and forming the flattened conical coil as just explained. The fuel discharge end 15 of the tubing 11 is a flattened nozzle 15a oriented to correspond with the flat cone so that the fuel jet from the nozzle into the cone is substantially correspondingly of a flat configuration, and so that the blast of fuel gas, air, and flame takes the shape of the flattened cone to provide for a fan-shaped blast of flame from the burner.

However, in so flattening the nozzle 15a, it is enlarged so that the inside area or passage thereof is substantially identical with the inside area or passage of the tube 11 at other points. By a selected form of flattening and configuration, and a selected spaced distance 18 from the rear end opening 17 of the coil, the pressure blast of the fuel from the nozzle will suck the proper amount of air with the fuel gas into the coil with the flattened jet of gas providing for effective mixing of air with fuel within the coil as the two ingredients pass through the interior of the burner head and combust. With the burning of that fuel mixture within the head, the fan-shaped flame will be ejected from the month end 16 of the burner.

In the operation of my burner, the fuel under pressure in the tank P flows as a liquid through the line L and into the stub pipe and thence through the tubing 11 of the coil and is ejected from the nozzle a as a flame when lighted. The force of the flame blast carries the flame through the cone 12, and that flame instantly heats the coil 12 and assures complete vaporization of the liquid propane fuel flowing into the coil. It is to be borne in mind that liquid propane fuel in the tank P is under pressure and that it will vaporize at reduced pressure whenever it is released as through the valve V. This evaporation is naturally accompanied by a refrigerating action which is offset by heating the coils 12 and such heating makes the evaporation complete and efficient.

The expansion of the liquid fuel into a gas effects a great increase in volume and a high velocity movement of the gas through the coils. The frictional resistance to the movement of the gas through the odd feet of tubing in the coil will create a back pressure which retards the flow of liquid fuel to the coil but ejects the gas at high velocity.

This movement of fuel gas through the tubing 11 at high velocity eliminates the need for a passage restriction at the nozzle such as a conventional jet orifice commonly used at burner nozzles. It was discovered that hydraulic frictional resistance to the flow of gas through the tubing could be used to effectively control and regulate the burners when a fuel such as propane is used.

It follows that the heat generating and flame throwing capacity of the unit is based upon the tubing size and not upon a nozzle size, as in conventional burners and that for comparative size, my improved burner head has a far greater heat or flame generating capacity than conventional restricted nozzle units. A much larger conventional burner is required to accomplish the same job that may be accomplished with my improved unit.

It will be apparent that there is a necessary desirable relationship between the inside diameter of the heated tubing 11 and the overall length thereof, if proper burning is to be obtained with the unrestricted nozzle 15a. In other words, because of the high velocity of gas through the tubing, a selected tube length is necessary to create a given back pressure or hydraulic resistance sufiicient for proper vaporization of fuel by the hot tubing 11, and to avoid any loss or dripping of liquid fuel at the nozzle 15a. In selecting a 40 foot length of A inch diameter tubing, it follows that the proper ratio between the inside diameter and tubing length is, for Ai-inch inside diameter tubing, approximately 1 to 1920. This proportion will be less for small diameter tubing and greater for larger diameter tubing, since the comparative hydraulic frictional resistance of the gas flowing through the tubing will decrease as the size of the tubing increases.

It is apparent that various changes and modifications may be made in the preferred embodiment of my invention, herein described in detail, which are within the teaching and scope of my invention, and therefore I wish to be bound only by the proper scope of the appended claims.

What I claim and desire to secure by Letters Patent is:

1. A burning apparatus utilizing liquified petroleum gas as a fuel, said apparatus comprising a tank containing said fuel in liquid form under pressure, a conduit connected to said tank and a burner unit connected to said conduit, said unit comprising a hollow flared coil formed of a continuous length of tubing of uniform interior cross section and having an inside diameter of the order of at least one quarter inch, the end of said tubing at the large end of said coil being connected to said conduit and the opposite end of said tubing being disposed on the longitudinal center line of said coil at the small end and in spaced relation thereto and providing a fuel discharge opening of the same cross sectional area as said tubing directed toward the small end of said coil, the ratio of the length of said tubing to the inside diameter of said tubing for a given fuel pressure being such that the total frictional resistance to the flow of fuel through said tubing and discharge opening is sufiicicnt to impede flow of fuel therethrough to the extent necessary to insure complete vaporization of said fuel in said coil and prevent discharge of liquid fuel through said discharge opening, said frictional resistance providing the sole means for controlling the flow of fuel through said tubing and discharge opening.

2. A burning apparatus as defined in claim 1 in which said ratio at said given pressure and for tubing having an inside diameter of one quarter inch is 1920 to 1.

References Cited in the file of this patent UNITED STATES PATENTS 872,920 Farley Dec. 3, 1907 1,338,653 Hardt et al. Apr. 27, 1920 1,837,030 Elze Dec. 15, 1931 2,220,738 Stoddard Nov. 5, 1940 2,601,895 Garretson et al. July 1, 1952 2,631,581 Skousgaard Mar. 17, 1953 FOREIGN PATENTS 4,132 Great Britain of 1900 20,024 Great Britain of 1892 104,659 Germany July 28, 1899 

